Abu Musa sought permission to enter upon Umar three times, but was not granted permission, so he left. Umar later met him and asked, "What happened? Why did you turn back?"Abu Musa replied, "I heard the Messenger of Allah ﷺ say, 'Whoever seeks permission three times and is not granted it should turn back.'"Umar said, "You must bring me proof of this, or I will deal with you severely."So Abu Musa went to the gathering of his people and implored them by Allah to confirm what he had heard. I said, "I will go with you." They testified on his behalf, and Umar let him go.
حدثنا يزيد أخبرنا داود عن أبي نضرة
استأذن أبو موسى على عمر رضي الله تعالى عنهما ثلاثا فلم يؤذن له فرجع فلقيه عمر فقال ما شأنك رجعت قال سمعت رسول الله ﷺ يقول من استأذن ثلاثا فلم يؤذن له فليرجع فقال لتأتين على هذا ببينة أو لأفعلن ولأفعلن فأتى مجلس قومه فناشدهم الله تعالى فقلت أنا معك فشهدوا له بذلك فخلى سبيله